Module 6. Public Domain
This module explains the basic concept of public domain and provides you with some introductory resources for finding public domain content.
Copyright law varies from country to country, but in the US, public domain is a technical term referring to works that are not subject to copyright protection.
In general, there are three groups of works that are in the public domain:
- Old works for which the copyright has expired;
- Exempt works that may not be copyrighted or that were created under certain conditions;
- Any works that have been released to the public domain by their authors.
Under the current US copyright law, any copyrighted work will automatically pass into the public domain 70 years after the death of the author. In general terms, this means that virtually all classics or materials older than 120 years or so are in the public domain. To determine if a specific work is in the public domain, however, you should find out when the author died and add 70 years in order to determine the date at which copyright expires. This time frame has gradually been lengthened in US history, so some works may still be in the public domain that were created less than 70 years ago.
For instance, the John Wayne and Maureen O'Hara movie McLintock! passed into the public domain in 1994.
Copyright can only be applied to specific types of works (e.g., books, movies, images) and cannot be applied to general knowledge. For this reason, you do not need to cite anyone when you state a fact (e.g., "Jupiter is a planet").
Works may also be exempt from copyright if they are created under certain conditions of employment. The most common example of this is when US federal employees create works as part of their jobs (e.g., active duty service men and women in the armed forces). Works that these individuals create (e.g., photos taken) may be placed in the public domain by virtue of their employment.
Any author of a work may willingly choose to release that work into the public domain by simply labelling the work (e.g., "this work is in the public domain"). By doing so, the author gives anyone (e.g., individuals, corporations) the right to use their work for any purpose, without limitation or attribution.
Since they are not subject to copyright protection, public domain works may be used for anything and may even be included in derivative works and may be sold. There are no restrictions on how these works may be used, so citations are not generally needed. However, if you are using public domain content in your own work, it would be helpful for others to know what parts are public domain so that they know how they might also reuse and remix your content.
Some example repositories of public domain content include the following:
- Project Gutenberg
- Army Photos
- Library of Congress
- Internet Archive
- U.S. Fish and Wildlife Digital Library
- Digital Public Library of America
- Which of the following works are in the public domain?
- Old works whose copyright has expired
- Exempt works
- Released works
- All of the above
- You know that a work is released to the public domain if:
- You cannot find a copyright © symbol on it
- The author recently died
- It is labeled as royalty free
- [None of the above]
- Public domain works may be used:
- For non-commercial purposes, as long as they are cited.
- For commercial purposes, as long as they are cited.
- For non-commercial purposes, even without being cited.
- For any purposes, even without being cited.
- d - All of these works are in the public domain.
- d - The only way to know if something has been released to the public domain is if it is labeled as such.
- d - Seriously. Use them for anything, and you don't even need to cite.